Fire Detection Systems
Fire Indicator Panels
A Fire Indicator Panel (FIP) can perform a number of functions. The first are most critical -
It receives information from devices designed to detect and report fires both to the occupants and to the Fire Brigade via 3rd party monitoring service.
Provides important information to first responders on the location of the detected fire/s.
Further to those functions, the panel -
Monitors the detecting devices operational integrity.
Provides for automatic control of fire safety equipment or systems,
Today there are two basic types of panels: conventional panels & addressable panels.
Conventional Panels
Conventional panels have an established history of use, and as a general rule, are used less frequently in large buildings than in the past, but are not uncommon on smaller projects such as small schools, stores, restaurants, and apartments.
A conventional fire alarm control panel employs one or more circuits, connected to initiating devices (usually smoke detectors, heat detectors, duct probe detectors, manual call point (red break-glass), and sometimes flame detectors) wired in parallel.
These sensors are designed to dramatically decrease the circuit resistance when the environmental influence (fire, smoke, flame, etc) on any sensor exceeds a predetermined threshold. In a conventional fire alarm system, the amount of data is limited to the number of circuits used.
To help identify the location and control of fire within a building, it is subdivided into detection zones. For instance, the levels of a multi-story building could be one type of zone boundary
An Initiating Device Circuit connected to multiple devices within the same detection zone, effectively provides 3 key pieces of information about that zone to the fire panel -
normal
fault
alarm
The state of each initiating device circuit within a zone displays at the fire panel using visible indications, such as a flashing LED/light or an LCD display.
Larger systems require finer diagnostic detail and control functions and achieve this by providing multiple initiating circuits within a common zone, each exclusively connected to a particular type of initiating device, or group of devices.
The amount of data, however, remains a function of the number of circuits employed.
Addressable panels
Addressable panels are usually more advanced than their Conventional Panel counterparts, with greater information capacity and control flexibility.
Addressable Fire Indicator Panels employ one or more Signalling Line Circuits (SLC) - usually referred to as loops or SLC loops - ranging between one and thirty.
Each SLC monitors the devices connected, which can number from a few devices to several hundred, depending on the manufacturer. Large systems may have multiple SLCs.
Each device on an SLC has its own address, and so the panel knows the state of each individual device connected to it. Common addressable input (initiating) devices include -
Smoke detectors
Heat detectors (both Rate of Rise and Fixed Temperature)
Manual call points or manual pull stations
Notification appliances
Responders
Fire sprinkler system inputs
Switches
Flow control
Pressure
Isolate
Standard switches
Monitor modules
Addressable output devices include -
Warning System/Bell relays
Door holder relays
Auxiliary (control function) relays
Control modules
Relay modules
Output devices are used to control a variety of functions such as -
Switching fans on or off
Closing/opening doors
Activating fire suppression systems
Activating notification appliances
Shutting down industrial equipment
Recalling elevators to a safe exit floor
Activating another fire alarm panel or communicator
Similar to Conventional Fire panels, zones are usually made by dividing a building or area into different sections. Then depending on the specific zone, a certain number and type of device is added to the zone to perform its given job.
‘Cause and Effect’ mapping is the process of activating outputs depending on which inputs have been activated. For instance, receipt of an initiating signal may lead to the shutdown of air conditioning and activation of smoke control exhaust fans and automatically open or close fire doors or shutters.
Emergency Warning & Intercommunication Systems
Emergency Warning System
The Emergency Warning System (EWS) generates and controls audible warning signals via dedicated amplifiers and loudspeakers installed on each level or in each zone of a building. Visual warning lights/strobes may also be installed in areas of high noise. On activation of a detector the EWS system will generate the standard "Alert" tone. After a predetermined period the system will switch automatically to the "Evacuation" tone interspersed with digitized voice messages instructing people to evacuate the building.
High-rise and other special building classifications may require the use of the automatic cascade sequence facility, whereby areas in immediate danger are evacuated first. Alert and Evacuate warning tones are automatically escalated at predetermined times until the whole building is evacuated in an orderly manner.
At any time authorised Fire Wardens or Fire-fighting Personnel may take control of the EWS system An emergency public address microphone allows the broadcast of verbal messages to building occupants in all or selected areas via the zone loud speakers. Under non-emergency conditions the EWS system may be used to distribute background music and routine public address announcements.
Emergency Intercommunication System
The Emergency Intercommunication System (EIS) provides dedicated emergency telephone communications between the Emergency Control Panel (ECP) and Fire Warden Intercommunication Points (WIPs) in each zone. Secondary ECPs Secondary Emergency Control Panels (SECPs) may be connected to allow control and monitoring of the complete EIS system from multiple locations.
Each SECP duplicates all the functions of the Master ECP. A priority system arbitrates handover control between the Master ECP and SECPs, and also allows a SECP to take full control should the Master ECP fail. Emergency Warning and Intercommunication System (EWIS) have been designed to facilitate the orderly and speedy evacuation of a building in the event of an emergency. This procedure may be initiated automatically by a fire alarm system or manually by a break glass call point. The EWS System may be used as a fully automated system or it will allow Fire Wardens to easily control and co-ordinate an evacuation using the dedicated emergency telephone network.
Smoke Alarms
A smoke alarm is critical for the early detection of a fire in your home and could mean the difference between life and death. In a fire, smoke and deadly gases tend to spread farther and faster than heat. That's one reason why most fire victims die from inhalation of smoke and toxic gases, not from burns.
The main argument behind the recommendation is that since ionization alarms typically respond faster to fast-fires and photoelectric alarms respond faster to smoldering fires, the presence of both types will be most effective in protecting a home
Two types of smoke alarms are commonly found in Australian homes; Photoelectric and Ionisation. It is important to note that currently both types can be legally purchased and used as both meet the required Australian Standard AS3786. However, for a number of years now photoelectric smoke alarms have been the only type recommended by Australian Fire Authorities and Fire Brigades, as well as the International Association of Fire Fighters.